Convert Month (month) to Year (Leap) (y (leap)) instantly.
About these units
Month (month)
A month traditionally reflects the lunar cycle, which lasts about 29.53 days (a synodic month). Ancient cultures used lunar months to track seasons, religious festivals, and agricultural cycles. In modern civil calendars, however, months are fixed lengths of 28–31 days to maintain alignment with the solar year. This creates a hybrid system: culturally grounded in the Moon, yet functionally tied to Earth's orbit around the Sun. Months remain one of the most intuitive time units for planning—budget cycles, billing periods, academic schedules, subscription systems, and medical dosing regimens all rely heavily on monthly intervals.
Year (Leap) (y (leap))
A leap year contains 366 days, occurring roughly every four years in the Gregorian calendar to correct for the fact that a tropical year is not exactly 365 days. Leap years prevent seasonal drift by compensating for the extra 0.2422 days in each solar year. Without leap-year corrections, seasons would shift by one full day every four years, eventually placing summer in December over the course of centuries. Leap years are essential to maintaining synchrony between human calendars and Earth's orbital mechanics, illustrating how civil timekeeping must regularly adjust for astronomical reality.